The universal properties of ceramics include mechanical strength in spite of brittleness, chemical durability, hardness and ability to be decorated. Ceramic products include porcelain (for figurines, vases, etc.), whiteware (dinnerware, sanitary ware, floor tile, etc.), structural products (brick, tile, terra cotta, etc.) and the like. These products are often referred to as pieces.
Many of the above pieces are produced using a mold and a ceramic slip. The ceramic slip is poured into a plaster of paris mold that draws enough water from the adjacent slip to build up a solid body layer on the mold. After the desired thickness of the solid body layer is obtained, the excess slip is poured off. The mold is parted and the solid body layer is removed and fired at an elevated temperature in an oven to cure the ceramic. If the body layer is not fired the ceramic will not cure. The firing process can be complex, requiring temperature changes throughout the firing process. If not performed properly, the piece can break during firing.
Problems exist with this production process. The mold walls must be thick because the slip has a high viscosity and a high specific gravity. A thick-walled mold is heavy making it difficult to use. The time required to build the solid body layer is relatively long, which increases the turn-around time before the mold can be used to produce the next copy of the piece. Firing is a costly process because of the expense of the oven, the time required to perform the firing and the breakage of pieces.
The ceramics industry is interested in entering new markets, such as making ceramics available to hobbyists. The use of a ceramic slip imposes the same problems to the hobbyist as it does to the ceramics industry. Hobbyists also do not want to spend time waiting for the solid body layer to form or for the firing to proceed. Furthermore, hobbyists often do not have access to the oven or the skill to properly fire the solid body layer. The added cost of firing is a detriment to the hobbyist's use of ceramics.
The ceramics industry has attempted to overcome the problems hobbyists face by premanufacturing the pieces for the hobbyist to paint. However, the satisfaction achieved by the hobbyist is not as great as when the hobbyist manufactures the piece. The industry is also faced with the above-described problems of mold wall thickness, build-up time and firing. To avoid the firing problems, the industry markets "greenware," which is an unpainted and unfired piece. Greenware merely shifts the firing problems from the industry to the hobbyist. An additional problem is that the pre-manufactured pieces can chip or break during shipping, rendering them useless.
An alternative has been to make the pieces out of plaster, as opposed to ceramics. The plaster pieces must be solid for strength, which increases their weight and hence the shipping costs. A rubber mold is used which provides less detail than the plaster mold. The plaster pieces are also subject to chipping and breakage.
The present invention is directed to solving one or more of the problems discussed above in a novel manner.